Interesting question. In australia there are laws to prevent the use of copyright circumventing technology. Given that unwrap could definitely be used to obtain amendable source code, then providing that as a service is certainly dubious. That said, there are services and software for cracking ZIP or MS-Office passwords.

If you are thinking of this as a 'paid-for' service, then you'd want some assurance that the requestor owns the rights to the code in question.